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Need help with room

I currently obtained a SPL meter and Rives test CD to try and diagnose why my system is fatiguing in the highs and lacks in the mid bass. When I performed the frequency analysis I noticed that I have a rather steep decline in decibels below 400 hz bottoming out at 125 hz and then rising a little to 100 hz then back down. On the other end I have a sharp decline above 6300 hz. The total swing in db from top to bottom is as much as 30 db btw. 50hz and 16k hz. I would like to smooth out the frequency response and have tried moving the speakers, but it mainly just moved the lowest point a few hz without really affecting the response more than a few db and I need a lot more. I also tried different interconnects with minimal success. I tried removing my home made acoustic panels that did change things, but not to the effect needed and panels will not compensate for my base suck out if that is what I have. I am curious about my source because it does seem to lack in the lower end when compared to other sources, but I would be supposed if they could be that different. If anyone has any ideas I would greatly appreciate it.
Thanks, David

Room is 10' x 11' with 8' ceilings. Speakers are set out on golden ratio from front and sidewalls. One large window with metal blinds and thin curtain on front wall.
Parasound A23/P3
Denon 3800 (source)
Audioquest cheetah and jaguar interconnects
Alpha core Python MI2 speaker cables
dhel

Showing 2 responses by shadorne

shadorne's avatar
shadorne
7,490 posts
 
A narrow spike at 630 Hz may be room related....try moving the SPL meter by 1 foot and see if the spike disappears. If it does then you may want to try acoustic treatments as an EQ will not solve that problem except at that exact listening position....and moving speakers or listening position around may simply move the null or spike to a slightly different frequency. (bear in mind your ears are about 6 inches apart and the wavelength of 630 Hz is a couple of feet)
shadorne's avatar
shadorne
7,490 posts
 
Are you using single frequency tones or warbled test tones? Single frequency tones can give some deep spikes/nulls which I would tend to ignore if they are very sharp....30 db swing from peak to trough in your size room is not surprising. Check out what Ethan Winer's or Realtraps website says about typical room response...it is a real eye opener....don't worry you are not alone in having discovered a far from flat room response.

The dip between 100 Hz and 400 Hz is very worrying if it is a continuous and deep trough as is the decline above 6300 Hz - unless you are talking only a few db average drop (say less than 6 db from average). Although you will always have peaks and troughs due to the room modal response, which in your case will be quite obtrusive (small and close to a cube in shape), you should aim for a broadly even response when taking an average....a little bass heavy and a little roll off in the treble seems to be what most people enjoy most.

Room treatments can help and so can a PEQ like the one made by Behringer... but your room may pose a challenge which you can only expect to mitigate.
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